Milling head

ABSTRACT

An improved milling head. A milling head is provided with a backing plate with a toothed system on the from side, whose teeth run in parallel to the longitudinal axis of the carrier body. Because the blade plate has a toothed system, which can be engaged with the toothed system on the front of the support plate, the blade plate no longer needs to be shifted radially outward to be resharpened. Rather the blade plate must only be radially displaced to the outside by a tooth of a micro-toothed system. This simplifies the regrinding on a constant flight circle diameter, because only the hard metal of the blade plate needs to be ground, which can be accomplished with a normal hard metal grinding wheel. The support plate only needs to be shaped when it is manufactured, which is possible with a normal corundum disk and can be accomplished quickly. Since the support plate does not need to be reground, it remains completely functional and can be used together with a new blade plate. In a preferred embodiment, the support plates and the flank of the groove which creates the face of the support plate provide for an interlocking securing device for the support plate against any dislocation in the radial direction relative to the carrier body.

BACKGROUND OF THE INVENTION

The invention relates to a milling head, which are used preferably forperipheral milling.

Normally milling heads of this kind have soldered blades, that is theblades are supplied with soldered hard metal cutting elements. Suchsoldered blades have a series of disadvantages. For example, fracturescan occur in the hard metal when grinding and reshaping. Furthermore,the grinding and reshaping is costly because combination hard metalgrinding wheels are required for this.

A known milling head of the already known type does not have thesedisadvantages (EP 0 345 570 A1), because the blade plate is not solderedto the support plate, but rather only lies on this. In addition to thefrictional force that occurs between the blade plate and the backingplate, because both are pressed together against the groove whichaccepts the edge by means of the pressure block, the blade plate isprotected from a radial shifting relative to the backing plate by agroove running in parallel to the longitudinal axis of the carrier body,into which a ridge-shaped section of the material of the backing plategrips. Namely, the support plate can be adjusted radially to the outsidetogether with blade plate tooth by tooth thanks to the toothed system onthe back side of the support plate which engages in a toothed system inthe edge of the groove, to achieve the original flight circle diameteragain when resharpening. When resharpening, the backing plate must becorrespondingly ground so that, when the blade plate can no longer besharpened, the backing plate must also become unusable. It isdisadvantageous in particular then that when one wishes to sharpen theblade plate and the support plate together, an expensive combinationhard metal grinding wheel must be used provided that the blade plateconsists of hard metal as is usual.

SUMMARY OF THE INVENTION

The invention has the task of creating a milling head that does not havethe disadvantages of these known milling heads.

By providing the backing plate with a toothed system on the front side,whose teeth nm in parallel to the longitudinal axis of the carrier body,and because the blade plate has a toothed system, which can be engagedwith the toothed system on the front of the support plate, the supportplate no longer needs to be shifted radially outward for reshapening theblade plate. Rather the blade plate must only be radially displaced tothe outside by a tooth of micro-toothed system. This simplifies theregrinding on a constant flight circle diameter, because only the hardmetal of the blade plate needs to be ground, which can be accomplishedwith a normal hard metal grinding wheel. The support plate only needs tobe shaped when it is manufactured, which is possible with a normalcorundum disk and can be accomplished quickly. Since the support platedoes not need to be reground, it remains completely functional and canbe used together with a new blade plate. In contrast to milling headswith soldered blades the solution in the invention has the advantagethat very hard varieties of hard metal that cannot be soldered can beused. Furthermore, the danger of creating fractures when grinding andreshaping no longer exists as with soldered blades. Since a hard metalgrinding wheel can be used for resharpening, a far higher quality ofgrinding on the back of the blade plate is possible to achieve than whengrinding with a combination grind stone. In a preferred illustrativeform, the support plates and the flank of the groove which creates theface of the support plate have a means for an interlocking securingdevice for the support plate against any dislocation in the radialdirection relative to the carrier plate. In this way it is alsoprevented that a preferably provided toothed system of the support plateand the groove edge be misused to be able to radially displace thesupport plate to the outside by one or more teeth.

An interlocking securing device against an axial shifting of the bladeplate relative to the backing plate is advantageous. It cannot lead thento a mispositioning of the blade plate in the axial direction due toinattention. Since its toothed system can engage with the toothed systemof the support plate only within the radial adjustment range of theblade plate, a clearly obvious gap exists between the blade plate andthe support plate when positioning the blade plate outside the radialadjustment range, which indicates to the user that the blade adjustmentrange has been exceeded. One can also provide an interlocking boundaryof the radial displacement of the blade plate relative to the backingplate to avoid too large a radial displacement. It is especiallyadvantageous when the backing plate has a pin overhanging its frontside, which is engaged in a slot which extends at a right angle to thelongitudinal extension of the teeth, because hereby an interlockingsecuring device against an axial shifting as well as against too large aradial displacement of the blade plate relative to the backing plate isachieved with very simply means.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in detail with the help of two illustrativeexamples as shown in the drawings.

FIG. 1 shows a partially cut end view of an incompletely outfitted firstillustrative example.

FIG. 2 shows an enlarged view from FIG. 1.

FIG. 3 shows a front view of the support plate of the first illustrativeexample.

FIG. 4 shows an top view of the support plate of the first illustrativeexample.

FIG. 5 shows a front view of the blade plate of the first illustrativeexample.

FIG. 6 shows an top view of the blade plate of the first illustrativeexample.

FIG. 7 shows an enlarged and incomplete side view of the blade plate ofthe second illustrative example.

FIG. 8 shows an enlarged and incomplete side view of the support plateof the second illustrative example.

FIG. 9 shows an excerpt from the top view of the second illustrativeexample.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, wherein like numerals represent likeelements throughout the several views, in FIG. 1 there is shown aprofile milling head for peripheral milling having a support body 1,which is provided with a central bore hole 2 through it for acceptanceof a shaft. Four like recesses 3 penetrate from the outer surface areainto the support body 1, which are evenly distributed over the perimeterand have the form of grooves which extend over the entire axial lengthof the support plate with an invariable shape.

As more clearly seen in FIGS. 1 and 2, these grooves have mutuallyparallel, even flanks that are inclined in the illustrative exampleagainst the radial plane, so that the outer rim advances against theinner rim. The flank 4 lagging in the rotational direction is providedwith micro-toothed system 5 over nearly its entire surface, the teeth ofwhich run parallel to the longitudinal axis of the support body. Betweenthe inner end of these micro-toothed system 5 and the groove base 6,which rises from the lagging flank 4 to the leading flank 7 by a step, apenetrating, groove-type indentation 8 is provided in the lagging flank4.

Several threaded bore holes 9, arranged at a distance from each other inthe axial direction of the carrier plate 1, open into the leading flank7, which open into the outer surface area of the support body 1 on theother side. The longitudinal axis of each of these threaded bore holes 9creates with the lagging flank 4 a sharp angle pointing away from thegroove base 6. In each threaded bore hole 9 a threaded pin 10 isarranged lying in it, the end piece of which is unthreaded and extendsinto the recess 3 in the illustrative example. The threaded pins 10 siton the base of a triangular groove, which is provided in the sidesurface of a pressure block 11, which extends along the entire axiallength of the support body 1. Except for this groove and a channel onthe radial side on the outside for the chucking groove the pressureblock 11 has a rectangular cross-section profile.

Between the side surface of the pressure block 11 the lagging flank 4 ablade plate 12 and a support plate 13 are arranged, which extend likethe pressure block 11 over the entire axial length of the supportplate 1. The support plate 13, which sits on the lagging flank 4, isprovided with a micro-toothed system 14 on its back side, which engagesin the micro-toothed system 5 of the lagging flank 4. The support plate13 has a ridge-shaped section of material 15 overhanging themicro-toothed system 14 adjacent the inner end of the micro-toothedsystem 14, which engages in the indentation 8 and through that excludesa radial adjustment of the support plate 13 to the outside relative tothe lagging flank 4.

The support plate 13 is provided with a micro-toothed system 16 on thelower end zone of its front side turned toward the leading flank 7, onwhich the back side of the blade plate 12 sits, the teeth of which runin the axial direction and extend along the entire axial length of thesupport plate 13. The micro-toothed system 16 juts out over the frontside of the support plate 13, so that a micro-toothed system 17 canengage in it, which is provided in the lower half of the back side ofthe blade plate 12 and extends along the entire axial length. Since bothmicro-toothed systems 16 and 17 serve to be able to adjust the bladeplate 12 radially to the outside tooth for tooth to be able to achievethe same flight circle diameter again as before when resharpening, thewidth of the zones with micro-toothed systems 16 and 17 is chosenaccording to the desired adjustment range.

To preclude an axial displacement of the blade plate 12 relative to thepressure plate 11 on the one hand and on the other hand to prevent theblade plate 12 from being able to be displaced to far to the outsiderelative to the support plate 13, a half-length taper-grooved dowel pin18 extending over the front side is inserted in the support plate 13,which is securely engaged in an oblong slot and extends perpendicular tothe longitudinal extension of the teeth of the micro-toothed systems 16and 17.

As is shown in FIG. 1, the blade plate 12 and the support plate 13 aremounted together in the openings, while the pressure block 11 is pressedagainst the lagging flank 7 by means of the threaded pin 10. In this waythe micro-toothed system 14 of the support plate 13 is held engaged withno movement with the micro-toothed system 5 of the lagging flank 4 aswell as the micro-toothed system 17 of the support plate. Should aresharpening of the blade plate 12 be required, then the tension isreleased as far as is needed to displace the blade plate 12 radially byone tooth to the outside relative to the support plate 13. The bladeplate is worked exclusively in the resulting resharpening. The supportplate 13 is only shaped during its manufacturing process. It maintains,therefore, its original form and thus can be used together with a new oranother blade plate 12, possibly of another material.

For the second illustrative example represented in FIG. 7 through 9, theblade plate 112 is provided with a toothed system 117 on its back sidewhich corresponds with the toothed system 17 in the first illustrativeexample, the teeth of which extend over the entire axial extension ofthe blade plate 112. As in the first illustrative example, the toothedsystem 117 ends at a distance from the radial inner edge of the backside of the blade plate 112. Like the toothed system 17 in the firstillustrative example, toothed system 117 is sunk completely in the backside of the blade plate 112, as FIG. 7 shows. Due to the smalldimensions of the tooth shapes the toothed system 117 can also bedescribed as micro-toothed system.

The toothed system 116 of the support plate 113, working together withthe toothed system 117, as FIG. 8 shows, juts out over the front side ofthe support plate 113. The number of teeth in the toothed system 116 issmaller, in the illustrative example half as much, as the number ofteeth in the toothed system 117. The blade plate 112 can then beadjusted by half the number of teeth of the toothed system 116 in theradial direction, shown in FIG. 9, which shows the blade plate 112 inthe position on the inner end of the adjustment range.

If the user selects a position for the blade plate that is outside theadjustment range of the blade plate, at least one of the teeth of thetoothed system 116 of the support plate comes into the arrangement onthe back side of the blade plate 112. Should it be a matter of positionin which the blade plate 112 is displaced over the adjustment rangeradially to the outside, at least one of the teeth of the toothed system116 come into the arrangement in the region 120 of the back side of theblade plate between the toothed system 117 and the inner edge of theback side of the blade plate 112. The arrangement of the teeth of thetoothed system 116 on the back side of the blade plate 112 results in agap between the blade plate 112 and the support plate 113. This gap isclearly recognizable and indicates to the user that the blade plate 112occupies an unacceptable position. Therefore an interlocking border ofthe adjustment range of the blade plate 112 in the radial direction iswithdrawn in the second illustrative example, as it exists in the firstillustrative example with the half length taper-groove dowel pin 18 andthe oblong slot 19.

As in the first illustrative example the back side of the support plate113 is provided with a toothed system 114 on its back side, whichengages with the toothed system 105, with which the lagging flank 104 inthe rotational direction of one of the grooves 103 is provided, whichthe carrier body 101 has.

Due to the remaining details, the first illustrative example isindicated for the illustration, since agreement with the firstillustrative example exists in as far as this.

Although certain presently preferred embodiments of the invention havebeen described herein, it will be apparent to those skilled in the artto which the invention pertains that variations and modifications of thedescribed embodiment may be made without departing from the spirit andscope of the invention. Accordingly, it is intended that the inventionbe limited only to the extent required by the appended claims and theapplicable rules of law.

I claim:
 1. Milling head comprising a carrier body having a perimeterhaving recesses dispersed evenly around said perimeter in an axialdirection of the carrier body for receiving a blade plate therein;saidblade plate being adjustable in a radial direction and being securedagainst axial shifting, by a support plate and a pressure block, whereinsaid pressure block presses said blade plate against said support plate;said support plate including a toothed system having multiple parallelteeth extending longitudinally on a front side thereof; said blade platehaving corresponding teeth on a back side thereof, wherein said teeth inopposing relation can be brought together and engaged at a predeterminedradial displacement of the blade plate relative to said support plate;and an interlocking securing device having an indentation having agroove shape and which prevents radial displacement of said supportplate; wherein said interlocking securing device comprises a toothedsystem on a back side of said support plate and corresponding teeth onone flank of the recess; wherein a dowel pin is provided which preventsaxial shifting of the blade plate relative to said support plate anddefines a range of adjustment of said blade plate in a radial direction;and wherein said dowel pin extends over a front side of said blade plateand is secured in a slot in said blade plate, said slot beingperpendicular to a longitudinal extension of the teeth of the toothedsystem of said blade plate.
 2. A milling head comprising:a carrier bodyhaving a longitudinal axis, an axial direction, a radial direction, aperimeter, and an outside, a blade plate having a front side and a backside, a support plate having a front side and a back side, a pressureblock, means for interlockingly securing the support plate, wherein saidcarrier body includes a plurality of recesses distributed evenly aroundthe perimeter, said recesses extending in the axial direction of thecarrier body, grooves having a pair of flanks and which are open on theoutside for receiving therein said blade plate adjustable in the radialdirection, said blade plate secured against axial shifting on the frontside of said supporting plate by means of said pressure block and atleast one screw, said screw engaging a threaded bore hole in the carrierbody, said bore hole penetrating one flank of the groove, said pressureblock and said screw providing tensile support against the other flankof said groove, wherein the support plate includes a toothed system madeof multiple parallel teeth running towards the longitudinal axis of thecarrier body on the support plate front side, the blade plate isprovided with a corresponding toothed system on the blade plate backside, wherein both toothed systems can be brought together and engagedwith a selectable radial displacement of the blade plate relative to thesupport plate, wherein the means for interlockingly securing the supportplate against displacement in the radial direction relative to thecarrier body are provided by the flank which creates a support surfacefor the back side of the support plate, said flank provided with atoothed system that has teeth in parallel to the longitudinal axis ofthe carrier body, with a corresponding toothed system on the back sideof the support plate which is engaged as said means for interlockinglysecuring of the support plate against a displacement in the radialdirection relative to the carrier body, and wherein the flank betweenthe inner end of its toothed system and the base of the recess has anindentation having a groove shape and extending in the direction of theteeth and the support plate in the junction on the inner end of itstoothed system on the back side has a section of material engaged withthe indentation; wherein said interlocking securing device comprises atoothed system on a back side of said support plate and correspondingteeth on one flank of the recess; wherein a dowel pin is provided whichprevents axial shifting of the blade plate relative to said supportplate and defines a range of adjustment of said blade plate in theradial direction; and wherein said dowel pin extends over the bladeplate front side and is secured in a slot in said blade plate, said slotbeing perpendicular to the longitudinal extension of the teeth of thetoothed system of said blade plate.
 3. Milling head as recited in claim2, wherein said toothed system of said blade plate ends at a distancefrom the radial inner edge of its back side.
 4. Milling head as recitedin claim 3, wherein said toothed system of the blade plate is whollyinternal and the toothed system of said support plate projects outwardlypast its non-tooth surface.